JSFiddle - React, Tailwind, and code Playground

HTML

<html>  
<head>
<title>Hi !!</title>
</head>
<body>
    i'm a body
</body>
</html>

CSS

#bodyContainer{
    color:#0099f9;
    font:bold 15px Arial;
    background:#000;
    }

#footer {
   color:#f0f;
   font:bold 15px verdana;
   background:#3f3f3f;
}

JavaScript

$(function() {
        $('body').wrapInner('<div id="bodyContainer"/>');
        $('<div />',{id:"footer",text :"i'm a footer"})
            .insertAfter('#bodyContainer');
    });